Garden Talk: November 8, 2007

From NGA Editors

Colorful Japanese Forest Grass

Japanese forest grass (Hakonechloa macra) is an attractive, clumping ornamental grass that looks stunning planted as a ground cover along a walkway or on a bank. The leaves are usually a bright green or yellow, but a new variety is much more showy, with burgundy-colored leaf blades.

Red Wind forest grass (Hakonechloa macra Beni Kaze) produces the same soft green leaf blades as other types of forest grass in summer, but once the cooler weather of autumn arrives, the leaf blades take on a burgundy color that compliments other fall foliage. Red Wind grows 2 to 3 feet tall and wide in light shade, and is hardy in USDA zones 5 to 9.

New Continuous Input Composter

With the bevy of fallen leaves, grass clippings, and old flower and vegetable plants, fall is a great time to compost yard waste. While there are many home compost units on the market, here is a new one that requires no turning and relies on gravity to transfer materials.

The Earthmaker Composter from New Zealand features a gravity-fed system with three connected chambers that allows the yard waste to slowly descend as it breaks down. It requires only a few minutes every few weeks to keep the system "cooking." Add kitchen scraps and yard waste to the top of the 47-inch-tall and 31-inch-wide composter. After three to five weeks, slide out the bottom panel in the top chamber and let the yard waste fall to the second chamber to continue decomposing. After another three to five weeks, push the partially decomposed compost from the second chamber into the third chamber where it will finish breaking down. The whole process takes about 10 weeks to create finished compost. While the organic matter is breaking down in the second and third chambers, you can add more to the top chamber to create a continuous flow of finished compost throughout the growing season.

The Earthmaker Composter holds up to 16 cubic feet of compost. In trials in England this system produced twice as much high-quality compost as the standard control compost bin.

Award-Winning Japanese Hornbeam

Since 1978 the Pennsylvania Horticultural Society has recognized outstanding trees, shrubs, and woody vines with a special gold medal award. The plants are evaluated for performance, pest and disease resistance, eye appeal, and hardiness in USDA zones 5 to 7. These often are underutilized plants in the landscape that should be receiving greater attention.

One of the most striking winners for 2008 is the Japanese hornbeam (Carpinus japonica). This deciduous tree -- shorter and more graceful than the native hornbeam -- grows 20 to 30 feet tall at maturity, making it an excellent landscape tree for small yards and roadsides. In spring the Japanese hornbeam produces thumb-sized, cone-shaped nutlets in shades of cream, tan, and green. These "fruits" eventually turn brown and decorate the tree until autumn, when the foliage steals the show by turning brilliant yellow. Japanese hornbeam is hardy in USDA zones 4 to 9. It grows best in full sun but can tolerate part shade, and it's adaptable to a wide range of soil conditions.

Sky Farming of the Future

Small-space gardeners with only a deck and patio have been told for years to utilize the vertical space above beds and planters for growing more plants. Now Dickson Despommier, professor of environmental health at Columbia University in New York, wants to take the concept a step further and create vertical farms to grow food in urban areas. In 50 years, 80 percent of the world population is expected to live in cities. Instead of creating more farmland that destroys natural ecosystems to feed this population, Despommier wants to construct skyscrapers that can grow food to feed these urbanites and reduce global warming.

Despommier has been working for six years to marry sustainable building design with growing food in urban areas. Through the use of high-tech architecture, engineering, and agricultural science, he expects to be developing skyscrapers for growing food in a city within 10 years. For example, Despommier believes that 150, 300-foot-tall sky farms could feed the entire city of New York in the future. These vertical farms could also reduce the use of fossil fuels and global warming since food no longer would need to be shipped into urban areas. This would allow farmland to return to forests, which trap carbon. Each tower would feature self-sustaining solar panels, wind spires, wastewater recycling, animals and plants, and a recycling processor turning waste organic matter into fuel. Despommier is currently looking for funding to build prototypes of the vertical farm.

For more on these vertical farms of the future, go to: Vertical Farms.

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